You may have heard the saying, "What goes up must come down." That certainly holds true when you think of a waterfall. But British scientists at the University of Bristol have made water defy gravity. They say vigorous shaking of the surface below a droplet causes it to compress, producing a force that drives the water uphill. The researchers do not completely understand why it happens. They say additional studies will be useful in understanding fluid motions and could help crime scene investigators with DNA evidence.